This invention relates to an electronic apparatus which can both measure weight and length of an object. More specifically, the invention relates to a battery-operated, hand held electronic apparatus which may be used to measure the weight and the length of a fish and which includes a digital readout to display the measured values. While, in the illustrated embodiment set forth in this disclosure, the apparatus is illustrated for weighing and measuring a fish, it should be understood that the apparatus is general in nature and may be used to measure the weight and/or length of other objects.
Prior art devices have been available for determining the weight of objects, such as a fish. These devices have generally been mechanical in nature and generally comprise a tension spring having a hook secured to one end thereof and having the other end thereof secured to an index finger. The spring will be extended as a function of the weight suspended from the hook so that the index finger slides along a linear scale to provide a readout value of the weight of the suspended object. Additionally, some of these prior art scales include a measuring tape whereby the length of a fish or other object suspended from the hook may be measured.
A disadvantage of these prior art apparatuses is that, due to the non-linear deflection of the spring, the weight cannot generally be determined accurately. Furthermore, the readout devices are generally quite compact so that the resolution of the apparatus is poor whereby small differences in weight between different objects are not easily measured or detected. Another disadvantage of these devices is that they have no memory so that the weight or length of a previously measured object is not recorded and can only be recalled by memory or by keeping a written record of the measurements. A still further disadvantage of these devices is that the readouts are analog based rather than digital so that the exact value of either the length or the weight of an object can only be approximated.
Prior art electronic weighing scales have also been provided. These scales are generally relatively complex and cumbersome so that they cannot be hand held and are not easily portable. Lastly, these devices generally do not include structure to both measure the weight and the length of an object nor structure to convert the indicated values from metric units to English units or vice versa. Such electronic scales are also subject to drift because of variations in ambient temperatures and aging of components and must, therefore, be calibrated before use.
It is, therefore, desired to provide an accurate electronic, hand-held, scale and length measurement apparatus, which includes a digital readout and a memory wherein previously read measurements may be stored from which they may be recalled, which can provide a readout in both metric and English units and which is automatically calibrated when power is applied to the unit.